JP4697737B2 - Method for producing leather-like sheet material - Google Patents

Description

The present invention relates to a method for producing a leather-like sheet material and a leather-like sheet material, and more particularly to a method for producing a leather-like sheet material obtained using a heat-sensitive coagulable polyurethane resin emulsion and a leather-like sheet material.

Conventionally, as a method for producing a leather-like sheet material, a method of applying a polyurethane resin as a binding agent to a fiber material substrate has been performed. In recent years, as a polyurethane resin, a shift from a conventional wet method using a polyurethane resin solution to a dry method using a polyurethane resin emulsion is progressing from the viewpoint of strengthening legal regulations for organic solvent reduction. However, the dry method using a polyurethane resin emulsion has the disadvantages that the sheet becomes hard, the texture is remarkably inferior, and the wear resistance is also deteriorated.

In order to improve the texture by a dry method using a polyurethane resin emulsion, the fiber material substrate is coated with an inorganic salt-containing polyurethane resin emulsion and thermally coagulated (see Patent Document 1). There has been proposed a method (see Patent Document 2) in which an inorganic salt-containing polyurethane resin emulsion is applied to the applied fiber material substrate and heat-sensitive coagulation is performed.
JP-A-6-316877 JP 2000-17581 A

However, in the methods proposed in Patent Document 1 and Patent Document 2, the texture and wear resistance are not improved, and in the method of Patent Document 2, it is necessary to add a step of applying a flexible water repellent. There was a problem that productivity was reduced.

As a result of intensive studies to solve this problem, the present inventors have reached the present invention.
That is, the present invention is a method for producing a leather-like sheet material by applying a heat-sensitive coagulable emulsion (A) to a fiber material substrate that has not been subjected to a flexible water-repellent treatment, and then heat-coagulating the material. Water-soluble emulsion (A) contains polyurethane resin (a), soft water repellent (b), nonionic surfactant (c) having a cloud point of 40 to 98 ° C. and inorganic salt (d) as essential components, and weight A method for producing a leather-like sheet material, wherein the ratio (b) / (a) is an emulsion of 0.005 to 0.2; a leather-like sheet material obtained by the production method; and the leather A leather-like sheet obtained by further post-processing the sheet material.

The method for producing a leather-like sheet material of the present invention does not require an additional step of applying a soft water repellent, is excellent in productivity, and the obtained leather-like sheet material is excellent in texture and abrasion resistance.

The present invention is described in detail below.
The method for producing a leather-like sheet material of the present invention is a method for producing a leather-like sheet material by applying a heat-sensitive coagulable emulsion (A) to a fiber material substrate that has not been subjected to a flexible water-repellent treatment and then thermally coagulating it. The heat-sensitive coagulable emulsion (A) comprises a polyurethane resin (a), a soft water repellent (b), a nonionic surfactant (c) having a cloud point of 40 to 98 ° C., and an inorganic salt (d). Is an emulsion having a weight ratio (b) / (a) of 0.005 to 0.2.

As the fiber material substrate used in the present invention, a nonwoven fabric, a knitted fabric or the like conventionally used for the fiber material substrate is used.
The nonwoven fabric may be one in which a woven fabric or the like is laminated inside or on the surface for the purpose of reinforcement or the like. The constituent fiber may be either a natural fiber or a chemical fiber. Examples of natural fibers include cotton, wool, silk, and asbestos. Examples of chemical fibers include regenerated fibers such as rayon and tencel, semi-synthetic fibers such as acetate and triacetate, and synthetic fibers such as polyamide, polyester, polyolefin, and acrylic. Moreover, it is also possible to use appropriately a fiber using a mixture of these.

The fiber material substrate used in the present invention is not previously treated with a flexible water repellent from the viewpoint of reducing processes and improving wear resistance.
In the present invention, a soft water repellent is included as one component in the heat-sensitive coagulable emulsion, and the fiber material substrate is impregnated with the heat-sensitive coagulable emulsion and processed to obtain improved wear resistance. Can do.
In other words, by using a fiber material base that has not been previously treated with a soft water repellent and including the soft water repellent as one component in the heat-sensitive coagulable emulsion, not only the process reduction but also the soft water repellent The sea-island structure dispersed in the polyurethane resin adheres to the fiber surface, increasing the cohesion, and the leather sheet material has sufficient breaking strength, and the flexible water repellent bleeds onto the polyurethane resin surface. Out, the urethane resin has a microporous structure, and at the same time, the flexible water repellent is unevenly distributed on the urethane resin surface, which is effective in improving the abrasion resistance of the resulting leather-like sheet material. Conceivable.

The heat-sensitive coagulable emulsion (A) in the present invention comprises a polyurethane resin (a), a soft water repellent (b), a nonionic surfactant (c) having a cloud point of 40 to 98 ° C., and an inorganic salt (d). Contains as an essential component.
The content of (a) in (A) is preferably 2 to 40% by weight, more preferably 3 to 30% (hereinafter, unless otherwise specified,% represents% by weight); Preferably content is 0.1-10%, more preferably 0.2-5%; content of (c) is preferably 0.1-10%, more preferably 0.2-5%; content of (d) Is preferably 0.05 to 5%, more preferably 0.1 to 2%, and the other components are aqueous media.
The total content of (a) to (d) in (A) is preferably 2.3 to 65%, more preferably 3.5 to 42%.
The weight ratio (b) / (a) in (A) is 0.005 to 0.2, preferably 0.01 to 0.15. When (b) / (a) is less than 0.005, the abrasion resistance is insufficient, and when it exceeds 0.2, the tactile sensation of the surface deteriorates.
Furthermore, the weight ratio (c) / (d) in (A) is preferably 0.1 to 2, and more preferably 0.2 to 1, from the viewpoint of storage stability.

Examples of the polyurethane resin (a) that is an essential component of (A) in the present invention include, for example, organic diisocyanate (a1), polymer polyol (a2), carboxyl group (—COOH), and / or sulfone group (—SO ₃ H). ) -Containing polyol or a salt thereof (a3) and, if necessary, a chain extender (a4) and / or a terminator (a5), and then, if necessary, neutralize a carboxyl group and / or a sulfone group It is formed by neutralization with (a6).
Hereinafter, each component will be described.

As the organic diisocyanate (a1), those conventionally used for polyurethane production can be used. Examples of (a1) include 6-20 aromatic diisocyanates, 2-18 carbon diisocyanates, 4-15 alicyclic diisocyanates (excluding carbon in the NCO group). , Aliphatic diisocyanates having 8 to 15 carbon atoms, modified products of these diisocyanates (carbodiimide-modified products, urethane-modified products, uretdione-modified products, etc.), and mixtures of two or more thereof.

Aromatic diisocyanates include 1,3- and / or 1,4-phenylene diisocyanate, 2,4- and / or 2,6-tolylene diisocyanate (hereinafter abbreviated as TDI), 2,4′- and / or 4 , 4'-diphenylmethane diisocyanate (hereinafter abbreviated as MDI), 4,4'-diisocyanatobiphenyl, 3,3'-dimethyl-4,4'-diisocyanatobiphenyl, 3,3'-dimethyl-4,4 Examples include '-diisocyanatodiphenylmethane and 1,5-naphthylene diisocyanate.

Aliphatic diisocyanates include ethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, dodecamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, lysine diisocyanate, 2,6-diisocyanatomethylcaproate, bis (2- Isocyanatoethyl) carbonate, 2-isocyanatoethyl-2,6-diisocyanatohexanoate, and the like.

Examples of the alicyclic diisocyanate include isophorone diisocyanate, 4,4′-dicyclohexylmethane diisocyanate, cyclohexylene diisocyanate, methylcyclohexylene diisocyanate, bis (2-isocyanatoethyl) -4-cyclohexylene-1,2-dicarboxylate, 2,5- and / or 2,6-norbornane diisocyanate and the like.
Examples of the araliphatic diisocyanate include m- and / or p-xylylene diisocyanate, α, α, α ′, α′-tetramethylxylylene diisocyanate, and the like.

Of (a1), preferred are aromatic diisocyanate and alicyclic diisocyanate, and particularly preferred are isophorone diisocyanate and 4,4′-dicyclohexylmethane diisocyanate.

Examples of the polymer polyol (a2) include polyether diol (a21), polyester diol (a22), and a mixture of two or more thereof.

Examples of the polyether diol (a21) include a compound having a structure in which an alkylene oxide (hereinafter abbreviated as AO) is added to an active hydrogen atom-containing bifunctional compound, and a mixture of two or more thereof.

Examples of the active hydrogen atom-containing bifunctional compound include dihydric alcohols, dihydric phenols, and dicarboxylic acids.
Examples of the dihydric alcohol include ethylene glycol, propylene glycol, 1,3-butylene glycol, 1,4-butanediol, 1,6-hexanediol, diethylene glycol, neopentyl glycol, bis (hydroxymethyl) cyclohexane and bis (hydroxyethyl). ) Benzene and the like. Examples of dihydric phenols include catephenol and hydroquinone, and bisphenols such as bisphenol A, bisphenol F, and bisphenol S. Examples of the dicarboxylic acid include aliphatic dicarboxylic acids such as succinic acid and adipic acid, and aromatic dicarboxylic acids such as phthalic acid and terephthalic acid.
Two or more kinds of the above-mentioned active hydrogen atom-containing bifunctional compounds can be used.

Examples of AO added to the active hydrogen atom-containing bifunctional compound include ethylene oxide (hereinafter abbreviated as EO), propylene oxide (hereinafter abbreviated as PO), 1,2-, 2,3- or 1,3-butylene oxide. , Tetrahydrofuran (hereinafter abbreviated as THF), styrene oxide, α-olefin oxide, epichlorohydrin, and the like.
AO may be used alone or in combination of two or more. In the latter case, block addition, random addition, or a mixture of both may be used.
Among these AOs, preferred are EO alone, PO alone, THF alone, combined use of PO and EO, and combined use of PO and / or EO and THF.
The addition of AO to the active hydrogen atom-containing bifunctional compound can be carried out by a usual method, and is carried out without a catalyst or in the presence of a catalyst (an alkali catalyst, an amine catalyst or an acidic catalyst).

Specific examples of (a21) include polyethylene glycol, polypropylene glycol, and polytetramethylene glycol, with polytetramethylene glycol being preferred.

The polyester diol (a22) includes a low-molecular diol and / or a condensed polyester diol (a221) obtained by reacting a polyether diol having a molecular weight of 1000 or less and a dicarboxylic acid, a low-molecular diol and a mixture thereof, and a lower alcohol (such as methanol). ) And a polylactone diol (a223) obtained by ring-opening polymerization of a lactone, and the like.

Examples of the low molecular diol include the aforementioned dihydric alcohols. Examples of the polyether diol having a molecular weight of 1,000 or less include polytetramethylene ether glycol, polypropylene glycol, polyethylene glycol, and a mixture of two or more thereof.
Dicarboxylic acids include aliphatic dicarboxylic acids (such as succinic acid, adipic acid, azelaic acid and sebacic acid), aromatic dicarboxylic acids (such as terephthalic acid, isophthalic acid and phthalic acid), and ester forming properties of these dicarboxylic acids. Derivatives [acid anhydrides and lower alkyl (C1-4) esters, etc.] and mixtures of two or more of these may be mentioned. Examples of the lactone include ε-caprolactone, γ-butyrolactone, γ-valerolactone, and a mixture of two or more thereof.

The polyesterification reaction may be performed by a conventional method, for example, a method of reacting (condensing) a low molecular weight diol and / or a polyether diol having a molecular weight of 1,000 or less with a dicarboxylic acid or an ester-forming derivative thereof, or an initiator (low It can be carried out by a method of adding a lactone to a molecular diol and / or a polyether diol having a molecular weight of 1,000 or less).

(A221) includes polyethylene adipate diol, polybutylene adipate diol, polyhexamethylene adipate diol, polyneopentylene adipate diol, polyethylene propylene adipate diol, polyethylene butylene adipate diol, polybutylene hexamethylene adipate diol and poly (polytetramethylene) Ethers) adipate-based condensed polyester diols such as adipate diol; azelate-based condensed polyester diols such as polyethylene azelate diol and polybutylene azelate diol; sebacate-based condensed polyester diols such as polyethylene sebacate diol and polybutylene sebacate diol It is done.

(A222) is a linear alkylene polyalkylene carbonate diol having 4 to 10 carbon atoms (hereinafter abbreviated as C4 to 10) (for example, polytetramethylene carbonate diol, polyhexamethylene carbonate diol, nonane diol). Polycarbonate diols, etc.), C4-10 branched alkylene polyalkylene carbonate diols (for example, 2-methylbutanediol polycarbonate diol, 2-ethylbutanediol polycarbonate diol, neopentyl glycol polycarbonate diol, 2-methylpentane) Diol polycarbonate diols, 3-methylpentanediol polycarbonate diols, and the like, and copolymers thereof.
Examples of (a223) include polycaprolactone diol.

Of the (a2), from the viewpoint of hydrolysis resistance and durability, the polycarbonate diol (a222) is preferable, more preferably polytetramethylene carbonate diol, polyhexamethylene carbonate diol, polycarbonate diols of 3-methylpentane diol, and these It is a copolymer.

The lower limit of the number average molecular weight (hereinafter abbreviated as Mn) of (a2) is preferably 500, more preferably 1,000, and the upper limit is preferably 20,000, more preferably 10,000, particularly preferably 3. , 000.
Mn of (a2) is determined from the hydroxyl value, and the hydroxyl value can be measured by the method defined in JIS-K0070-1992 (potentiometric titration method).

The carboxyl group and / or sulfone group-containing polyol or salt (a3) is a component used for introducing a carboxylate group or a sulfonate group for the purpose of self-emulsifying the polyurethane resin in water.

Examples of (a3) include carboxyl group-containing polyol (a31) [dialkylol alkanoic acid {C6-24, such as 2,2-dimethylolpropionic acid (hereinafter abbreviated as DMPA), 2,2-dimethylolbutane. Acid, 2,2-dimethylolheptanoic acid, 2,2-dimethyloloctanoic acid, etc.]], sulfone group-containing polyol (a32) [sulfonic acid diol {3- (2,3-dihydroxypropoxy) -1-propanesulfone Acid etc.} and sulfamic acid diol {N, N-bis (2-hydroxyalkyl) sulfamic acid and its AO adduct} etc.], and combinations of two or more thereof.
Examples of the salt in (a3) include ammonium salts and amine salts [C1-12 primary amines (primary monoamines such as methylamine, ethylamine, propylamine and octylamine) salts, secondary monoamines (dimethylamine, diethylamine and Dibutylamine) salts, tertiary monoamines (trimethylamine, triethylamine, triethanolamine, N-methyldiethanolamine and aliphatic tertiary monoamines such as N, N-dimethylethanolamine; heterocycles such as N-methylpiperidine and N-methylmorpholine Tertiary monoamines of formula; aromatic ring-containing tertiary monoamines such as benzyldimethylamine, α-methylbenzyldimethylamine and N-dimethylaniline) salts], alkali metal (sodium, potassium and lithium) salts, and A combination of two or more compounds, etc. these are exemplified.
Among the salts, preferred are amine salts, more preferred are aliphatic tertiary monoamine salts, and particularly preferred are triethylamine salts.

The chain extender (a4) includes C2-10 diamines (for example, ethylenediamine, propylenediamine, hexamethylenediamine, isophoronediamine and toluenediamine); polyamines (for example, diethylenetriamine, triethylenetetramine, etc.); hydrazine or its derivatives (Dibasic acid dihydrazide such as adipic acid dihydrazide); C2-15 polyhydric alcohols [the above dihydric alcohols, trihydric alcohols (such as glycerin, trimethylolpropane, etc.), EO and / or of these polyhydric alcohols] PO low molar adducts (molecular weight less than 500)], and combinations of two or more thereof. Of these, ethylenediamine and isophoronediamine are preferred.

As the terminator (a5), C1-8 monoalcohols (methanol, ethanol, isopropanol, butanol, cellosolves, carbitols, etc.), C1-10 monoamines (monomethylamine, monoethylamine, monobutylamine, dibutylamine) , Monooctylamine, monoethanolamine, diethanolamine and the like), and combinations of two or more thereof. Of these, monoethylamine, monobutylamine and monoethanolamine are preferred.

When (a3) is not a salt and is a carboxyl group and / or sulfone group-containing polyol, the carboxyl group and / or sulfone group is neutralized using (a6) to form a carboxylate group and / or a sulfonate group. can do.
Examples of the neutralizing agent (a6) include alkaline compounds such as ammonia, amines [C1-12 primary amines (primary monoamines such as methylamine, ethylamine, propylamine and octylamine), secondary monoamines (dimethylamine). Amines, diethylamine and dibutylamine), tertiary monoamines (trimethylamine, triethylamine, triethanolamine, aliphatic tertiary monoamines such as N-methyldiethanolamine and N, N-dimethylethanolamine; N-methylpiperidine and N-methylmorpholine, etc. Heterocyclic tertiary monoamines; aromatic tertiary compounds such as benzyldimethylamine, α-methylbenzyldimethylamine, and N-dimethylaniline]], alkali metals (sodium, potassium and lithium) , Alkali metal hydroxides, as well as combination of two or more thereof. Of these, preferred are amines, more preferred are aliphatic tertiary monoamines, and particularly preferred is triethylamine.

The total amount of the above (a4) and (a5) is usually 0 to 100% equivalent based on the equivalent of the prepolymer terminal NCO group, preferably 20 to 80% equivalent, more preferably from the viewpoint of resin strength. 30-70% equivalent.
Moreover, the usage-amount of (a6) in neutralization is 20-200 mol% normally based on the sum total of a carboxyl group and a sulfone group, Preferably it is 30-150 mol%. When the amount of (a6) used is 30 mol% or more, it is preferable from the viewpoint of storage stability of the aqueous dispersion, and when it is 150 mol% or less, it is preferable from the viewpoint of the viscosity of the aqueous dispersion.

In the present invention, (a) preferably has a carboxylate group and / or a sulfonate group based on the weight of the polyurethane resin (a), preferably 0.01% or more, more preferably 0.05% or more, and particularly preferably It contains 0.08% or more, preferably 1.5% or less, more preferably 0.75% or less, and particularly preferably 0.50% or less. If the content of carboxylate groups and / or sulfonate groups is less than 0.01%, stable (A) tends to be difficult to obtain, and if it exceeds 1.5%, the water resistance of the formed resin film tends to decrease. .
The content of the carboxylate group and sulfonate group in (a) was determined by drying the residue obtained by heating and drying 3 to 10 g of (A) at 130 ° C. for 45 minutes, followed by washing and drying again at 130 ° C. for 45 minutes. It can be calculated from the acid value dissolved in dimethylformamide and measured by the method described in JIS-K0070 (potentiometric titration method).

Mn of (a) can be measured by gel permeation chromatography (hereinafter abbreviated as GPC).
In the case of non-crosslinked (thermoplastic) (a), Mn is preferably 2,000 to 2,000,000 or more, more preferably 10,000 to 1,500,000, and particularly preferably 100. , 000 to 500,000. In the case of the crosslinking type (a), Mn higher than the above range or high Mn that cannot be measured by GPC may be used.

In the urethanization reaction for obtaining (a) in this invention, in order to accelerate reaction, you may use the catalyst used for a normal urethane reaction if necessary. Examples of the catalyst include amine catalysts such as triethylamine, N-ethylmorpholine, triethylenediamine, and cycloamidines described in US Pat. No. 4,524,104 [1,8-diaza-bicyclo (5,4,0) undecene-7 ( San-Apro / Manufacturing, DBU), etc.]; tin-based catalysts such as dibutyltin dilaurate, dioctyltin dilaurate and tin octylate; titanium-based catalysts such as tetrabutyl titanate.

The production of (a) in the present invention includes the following two methods.
(1) A prepolymer of a terminal isocyanate group (hereinafter abbreviated as a terminal NCO group urethane prepolymer) is prepared in advance, and a dispersion medium and, if necessary, an emulsifier (a7), a chain extender (a4) and / or A method of emulsifying in the presence of a terminator (a5) and the like and obtaining it in the form of an emulsion of (a).
(2) A method in which a polyurethane resin having a terminal hydroxyl group is produced and obtained in the form of an emulsion (a) in the presence of a dispersion medium and, if necessary, an emulsifier (a7).
Among these, the method (1) is preferable.

The terminal NCO group urethane prepolymer in the method (1) is in the presence or absence of an organic solvent (acetone, methyl ethyl ketone, tetrahydrofuran, N, N-dimethylformamide, etc.) that does not contain an active hydrogen-containing group in the molecule, The active hydrogen component consisting of (a1) and (a2) and (a3) has a (NCO / hydroxyl group) equivalent ratio of usually 1.05 to 2.0, preferably 1.1 to 1.6. The reaction is usually performed at 20 ° C. to 150 ° C., preferably 60 ° C. to 110 ° C., and then neutralized with (a6) by a shot method or a multistage method.

Moreover, what is used as a dispersion medium required for manufacture of an emulsion normally includes water and a hydrophilic organic solvent. Examples of hydrophilic organic solvents are those having a solubility in water of 30/100 g water, such as monohydric alcohols (methanol, ethanol, isopropanol, etc.), glycols (ethylene glycol, propylene glycol, diethylene glycol, etc.), trihydric alcohols or more. (Glycerol etc.) and cellosolves (methyl cellosolve and ethyl cellosolve etc.) are mentioned. Of the dispersion media, preferred is water. When a hydrophilic organic solvent is used in combination, the hydrophilic organic solvent is usually preferably 10% or less based on the total dispersion medium.

The emulsion in the method (2) is obtained from (a1), (a2) and (a3) in the presence or absence of an organic solvent containing no active hydrogen-containing group in the molecule. The active hydrogen component is reacted with a one-shot method or a multistage method in an (NCO / hydroxyl group) equivalent ratio in the range of 0.5 to 0.99 to obtain a urethane polymer having a terminal hydroxyl group. It is obtained by adding.

As the emulsifier (a7) that can be used in the above methods (1) and (2), a nonionic surfactant (c) having a cloud point of 40 to 98 ° C., other nonionic surfactants (described later) a71), anionic surfactant (a72), cationic surfactant (a73), amphoteric surfactant (a74), and polymeric emulsifying dispersant (a75), such as US Pat. No. 3,929,678 and US Pat. The thing of patent 4331447 specification is mentioned. Two or more of these can be used in combination.
Among (a7), the following (c) is preferable from the viewpoint of heat-sensitive coagulation.

(A71) is a nonionic interface that does not have a cloud point or has a cloud point of less than 40 ° C. or more than 98 ° C. among alkylene oxide addition type nonionic surfactants and polyhydric alcohol type nonionic surfactants. An activator is mentioned.
Examples of the alkylene oxide addition type nonionic surfactant of (a71) include aliphatic alcohol EO addition products, phenol EO addition products, nonylphenol EO addition products, alkyl (C8-22) amine EO addition products, and polypropylene glycol EO addition products. Among them, nonionic surfactants having no cloud point or having a cloud point of less than 40 ° C. or more than 98 ° C. (for example, nonylphenol EO 50 mol adduct, etc.) can be mentioned. Examples of the polyhydric alcohol type nonionic surfactant include fatty acid (C8-24) esters (for example, glycerin monostearate, glycerin monooleate, sorbitan) of polyhydric (3 to 8 or more) alcohols (C2 to 30). Monolaurate and sorbitan monooleate), alkyl (C4-24) poly (degree of polymerization 1-10) glycosides and the like.

As (a72), an ether carboxylic acid having a C8-24 hydrocarbon group or a salt thereof [sodium lauryl ether acetate, (poly) oxyethylene (addition mole number 1 to 100) sodium lauryl ether acetate, etc.]; C8-24 Sulfate ester or ether sulfate ester having a hydrocarbon group and salts thereof [sodium lauryl sulfate, (poly) oxyethylene (addition mole number 1 to 100), sodium lauryl sulfate, (poly) oxyethylene (addition mole number 1 to 100) ) Lauryl sulfate triethanolamine, (poly) oxyethylene (addition mole number 1 to 100) coconut oil fatty acid monoethanolamide sodium sulfate, etc.]; sulfonate having C8-24 hydrocarbon group [sodium dodecylbenzenesulfonate, etc.] ] C8-24 hydrocarbon group 1 or 2 sulfosuccinates; phosphate esters or ether phosphates having C8-24 hydrocarbon groups and their salts [sodium lauryl phosphate, (poly) oxyethylene (addition mole number 1 to 100) lauryl Sodium ether phosphate and the like]; fatty acid salt having a C8-24 hydrocarbon group [sodium laurate, triethanolamine laurate and the like]; and acylated amino acid salt having a C8-24 hydrocarbon group [coconut oil fatty acid methyl] Taurine sodium, coconut oil fatty acid sarcosine sodium, coconut oil fatty acid sarcosine triethanolamine, N-coconut oil fatty acid acyl-L-glutamic acid triethanolamine, N-coconut oil fatty acid acyl-L-glutamic acid sodium, lauroylmethyl-β-alanine sodium etc ].

(A73) includes quaternary ammonium salt type [stearyl trimethyl ammonium chloride, behenyl trimethyl ammonium chloride, distearyl dimethyl ammonium chloride, ethyl lanolin sulfate fatty acid aminopropylethyl dimethyl ammonium, etc.]; and amine salt type [diethylaminoethyl stearate] Amide lactate, dilaurylamine hydrochloride, oleylamine lactate, etc.].

(A74) is a betaine-type amphoteric surfactant [coconut oil fatty acid amidopropyldimethylaminoacetic acid betaine, lauryldimethylaminoacetic acid betaine, 2-alkyl-N-carboxymethyl-N-hydroxyethylimidazolinium betaine, laurylhydroxysulfo Betaine, lauroylamidoethylhydroxyethylcarboxymethylbetaine sodium hydroxypropyl phosphate and the like]; and amino acid type amphoteric surfactants [sodium β-laurylaminopropionate and the like].

As (a75), polyvinyl alcohol; starch and derivatives thereof; cellulose derivatives such as carboxymethylcellulose, methylcellulose, and hydroxyethylcellulose; carboxyl group-containing (co) polymers such as sodium polyacrylate, Mn = 1,000 to 50,000 And a polymer type dispersant having a urethane bond or an ester bond described in US Pat. No. 5,906,704 [for example, a polycaprolactone polyol and a polyether diol linked with a polyisocyanate] and the like.

The soft water repellent (b) which is an essential component of (A) in the present invention is not particularly limited as long as it is a compound conventionally used as a soft water repellent. For example, a silicone compound (b1) and a fluorine compound (B2) etc. are mentioned. These may be used alone or in combination of two or more.

Examples of the silicone compound (b1) include polysiloxane and modified silicone oil. Examples of the polysiloxane include dimethyl polysiloxane, methylphenyl polysiloxane, methyl hydrogen polysiloxane, and diorganopolysiloxane diol. Examples of the modified silicone oil include epoxy-modified silicone oil, alkyl-modified silicone oil, alkylaralkyl-modified silicone oil, amino-modified silicone oil, carboxyl-modified silicone oil, alcohol-modified silicone oil, fluorine-modified silicone oil, and polyether-modified silicone oil. It is done.

Examples of the fluorine compound (b2) include fluoroalkyl ester polymers of acrylic acid (for example, 1,1-dihydroperfluorooctyl acrylate polymer, perfluoroalkylethyl acrylate-alkyl acrylate copolymer, etc.) and the like.

Of these, preferred is (b1), more preferred is polysiloxane, and particularly preferred are dimethylpolysiloxane, methylphenylpolysiloxane, methylhydrogenpolysiloxane, and combinations thereof.

(B) may be in the form of a silicone compound or fluorine compound itself, but may be in the form of an emulsion emulsified and dispersed in an aqueous medium. From the viewpoint of ease of addition, the form of an emulsion is preferable.
Examples of the emulsifier that can be used in the emulsion (b) include the same emulsifiers (a7) as mentioned in the production of the emulsion (a).
In the emulsion type (b) commercial product, as a silicone compound, “SM8706” [manufactured by Toray Dow Corning Co., Ltd., active ingredient 35%], “KM797” [manufactured by Shin-Etsu Chemical Co., Ltd., active ingredient 38%] ], Etc., "Dickguard F-90N" [Dainippon Ink Chemical Co., Ltd., active ingredient 20%] etc. are mentioned.

As nonionic surfactant (c) which has a cloud point of 40-98 degreeC which is an essential component of (A) in this invention, the cloud point of 40-98 degreeC among nonionic surfactants may be used. Although not particularly limited, a polyethylene glycol type nonionic surfactant is preferable. Moreover, a cloud point becomes like this. Preferably it is 42-95 degreeC, More preferably, it is 42-80 degreeC. When the cloud point of (c) is less than 40 ° C., there is a problem in storage stability such as generation of a solidified product when (A) is stored for a long time. On the other hand, when the cloud point exceeds 98 ° C., the affinity of polyurethane for water becomes too large, and (A) becomes difficult to thermally coagulate.
The cloud point can be measured by heating a 2% aqueous solution of a nonionic surfactant with stirring and reading the temperature at which it becomes cloudy with a thermometer.
(C) may be used as an emulsifier during the production of the emulsion (a) or (b) described above, or may be newly added and blended after the production of the emulsion.

Specific examples of (c) include aliphatic alcohol EO adduct [oleyl alcohol EO 11 to 16 mol adduct (cloud point 78 to 93 ° C.), lauryl alcohol EO 8 to 11 mol adduct (cloud point 70 to 98 ° C.), etc. Alkyl (C8-22) phenol EO adduct [octylphenol EO 9.5-14 mol adduct (cloud point 65-94 ° C.) and nonylphenol EO 10-15 mol adduct (cloud point 64-96 ° C.), etc.]; alkyl (C8-22) amine EO adducts; and polypropylene glycol EO adducts [polypropylene glycol (Mn = 700) EO 20-30 mol adducts, etc.], and these EO adducts are small amounts (30 mol% or less). It may be a random or block adduct with PO.

The lower limit of HLB in (c) is preferably 10, more preferably 11, particularly preferably 12, and the upper limit is preferably 17, more preferably 16, and particularly preferably 15. If HLB of (c) is 10 or more, even when the emulsion is stored for a long time, a solidified product is not generated, and it is preferable because it is excellent in storage stability. On the other hand, if the HLB is 17 or less, it is preferable because the emulsion easily heat-coagulates when heated.

HLB in the present invention is a value calculated by the following Griffin method described in Takehiko Fujimoto, “Introduction to New Surfactant”, published by Sanyo Chemical Industries, Ltd. (1992), P128.
HLB = (weight% of hydrophilic group) × (1/5)

Examples of the commercially available product (c) include the following aliphatic alcohol EO adducts.
“Emalmin NL-70”; EO adduct of C12 higher alcohol, cloud point = 44 ° C., HLB = 12.4, “Emalmin 110” manufactured by Sanyo Chemical Industries, Ltd .; EO adduct of C16-18 higher alcohol , Cloud point = 56 ° C., HLB = 13.2, “Narrow Acty N-120” manufactured by Sanyo Chemical Industries, Ltd .; C14-15 higher alcohol EO adduct, cloud point = 77 ° C., HLB = 14.2. “Emalmin 140” manufactured by Sanyo Chemical Industries, Ltd .; EO adduct of C16-18 higher alcohol, cloud point = 80 ° C., HLB = 14.2, manufactured by Sanyo Chemical Industries Co., Ltd.

Examples of the inorganic salt (d) that is an essential component of (A) in the present invention include the following inorganic salts having a solubility in water of 25 ° C. of 1 or more, preferably 10 or more. Moreover, (d) has the effect | action which solidifies an emulsion, For example, the following are mentioned.

Alkali metal salt (d1);
Alkali metal hydroxides [sodium hydroxide, potassium hydroxide and lithium hydroxide], alkali metal carbonates [sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate and lithium carbonate], alkali metal sulfates [sodium sulfate and Potassium sulfate], alkali metal nitrates [sodium nitrate and potassium nitrate], alkali metal phosphates [sodium phosphate, sodium hydrogen phosphate and potassium phosphate], alkali metal sulfites [sodium sulfite, sodium hydrogen sulfite and potassium sulfite] and Alkali metal halides (chlorine, bromine, iodine or fluorine) [sodium chloride, potassium chloride, sodium bromide, potassium iodide and potassium fluoride] and the like.
Alkaline earth metal salt (d2);
Alkaline earth metals (calcium, magnesium, barium, strontium, etc.) hydroxide [calcium hydroxide, magnesium hydroxide and strontium hydroxide], alkaline earth metal carbonates [calcium carbonate and magnesium carbonate], alkaline earth metal sulfuric acid Salts [calcium sulfate and magnesium sulfate], alkaline earth metal nitrates [calcium nitrate and magnesium nitrate], alkaline earth metal phosphates [calcium hydrogen phosphate and magnesium hydrogen phosphate], alkaline earth metal sulfites [calcium sulfite] And magnesium sulfite] and alkaline earth metal halides (chlorine, bromine, iodine or fluorine) [calcium chloride, magnesium chloride, calcium bromide, calcium iodide and magnesium fluoride] and the like.
Ammonium salt (d3);
Halogenated ammonium salts (such as ammonium chloride and ammonium bromide).
Among these, (d1) is preferable from the viewpoint that the emulsion is likely to obtain relatively long-term storage stability.

The method for preparing the heat-sensitive coagulable emulsion (A) of the present invention is not particularly limited, but from the viewpoint of storage stability, a method of adding (d) to the emulsion comprising (a), (b) and (c). preferable.

Examples of the method for adjusting the emulsion comprising (a), (b) and (c) include the following methods.
(1) A method of adding the emulsion of (b) and (c) to the emulsion of (a).
(2); after mixing (c) and (a7) if necessary with any one or more of the terminal hydroxyl group polyurethane resin, terminal NCO group urethane prepolymer or dispersion medium and emulsifying them in the dispersion medium, A method of adding the emulsion of (b).
(3): A method in which (c) and, if necessary, (a7) are mixed with either a terminal hydroxyl group polyurethane resin or a terminal NCO group prepolymer, and this is dispersed in the emulsion of (b) and emulsified.
(4): After mixing (b) with either a terminal hydroxyl group polyurethane resin or a terminal NCO group prepolymer, add (c) and mix, and then add only water or a mixture of water and (c). Emulsifying method.
(5) A method in which either (b) a terminal hydroxyl group polyurethane resin or a terminal NCO group prepolymer is mixed and then emulsified by adding a mixture of water and (c).
Among these, the method (2) is preferable from the viewpoint of the storage stability of (A).

The apparatus that can be used in the mixing / emulsification step in the present invention is not particularly limited, and examples thereof include an emulsifier of the following method: 1) vertical stirring method, 2) rotor-stator method [for example, “Ebara” Milder "(manufactured by Ebara Seisakusho)], 3) Line mill system [for example, line flow mixer], 4) Static tube mixing type [for example, static mixer], 5) Vibration type [for example," VIBRO MIXER "(manufactured by Chilling Industries, Ltd.) ], 6) Ultrasonic impact type [for example, ultrasonic homogenizer], 7) High pressure impact type [for example, Gaurin homogenizer (Gaurin)], 8) Membrane emulsification type [for example, membrane emulsification module], and 9) Centrifugal thin film contact type [ For example, fill mix]. Of these, 1), 2) and 9) are preferred.

In the present invention, the thermal coagulation temperature (A) is preferably 35 to 90 ° C, more preferably 40 to 80 ° C, from the viewpoint of storage stability and coagulation property. That is, it is preferable to solidify when the temperature of the heat-sensitive coagulable emulsion (A) itself is 35 to 90 ° C.
The thermosensitive coagulation temperature can be measured by heating the emulsion and reading with a thermometer the temperature at which the coagulation flow stops.

The volume average particle diameter of (A) in the present invention is preferably 0.01 μm to 1 μm, more preferably 0.02 μm to 0.5 μm. In addition, the said volume average particle diameter means the volume average particle diameter of the dispersoid currently disperse | distributed in the dispersion medium in an emulsion.
The volume average particle diameter can be measured using an ELS-800 electrophoretic light scattering photometer manufactured by Otsuka Electronics Co., Ltd.

The breaking strength of the film obtained by leaving (A) in the present invention at room temperature (25 ° C.) for 24 hours and further drying at 105 ° C. for 3 hours is preferably 10 to 100 MPa, more preferably 20 to 60 MPa. In addition, you may use a film-forming auxiliary | assistance for preparation of a film as needed.
The breaking strength can be measured by the following method. The film obtained with the No. 3 dumbbell cutter was cut into a test piece, which was pulled using an autograph {AGS-500D, manufactured by Shimadzu Corporation} at a pulling speed of 300 mm / min. taking measurement. This test is carried out under conditions of a temperature of 25 ° C. and a relative humidity of 65% RH, and it is necessary to adjust the temperature of the test sample under the same conditions for 2 hours or more before the measurement.

In (A) in the present invention, if necessary, a colorant such as titanium oxide, an ultraviolet absorber (benzophenone-based, benzotriazole-based, etc.) or an antioxidant [triethylene glycol-bis [3- (3-t-butyl]. Various stabilizers such as hindered phenols such as -5-methyl-4-hydroxyphenyl) propionate] and organic phosphites such as triphenyl phosphite and trichloroethyl phosphite], preservatives, cross-linking agents (polyepoxy compounds, Polyisocyanate compounds, etc.), inorganic fillers (calcium carbonate, etc.) and the like can be added.
The total amount of these additives is preferably 5 parts by weight or less, and more preferably 0.1 parts by weight or more and 3 parts by weight or less with respect to 100 parts by weight of the solid content of (A).

Application of (A) to the fibrous material substrate in the present invention is performed by impregnation or coating, and any method can be used as long as it is a commonly performed method.
For example, a method of impregnating (A) into a fiber material substrate and squeezing with a mangle or the like to prepare a pickup, and other methods such as knife coating, air knife coating, roll coating and spray coating can be mentioned.

Examples of the coagulation and drying method of (A) applied to the substrate include (1) a method in which heated steam is blown to heat-coagulate and then heat drying or air drying with a drying device, and (2) in the drying device. The method of introducing as it is, solidifying by heating and drying, etc. are mentioned. Among these, the method (1) is preferable.

The temperature of the atmosphere for thermally coagulating (A) applied to the substrate is preferably 40 to 180 ° C., more preferably 60 to 60 ° C., from the viewpoint of quickly completing the coagulation bath stability and coagulation of the polyurethane resin. 150 ° C., particularly preferably 70 to 120 ° C. The time for heat-sensitive coagulation varies depending on the temperature, but is usually 0.1 minutes to 30 minutes, preferably 0.5 minutes to 20 minutes.

The drying temperature after solidification is usually 100 to 200 ° C, preferably 120 to 180 ° C. The drying time is usually 1 to 60 minutes, preferably 2 to 30 minutes.

The leather-like sheet material of the present invention is obtained by the above production method.
The weight of the polyurethane resin (a) attached to the fiber material substrate is preferably 3 parts by weight or more, more preferably 10 parts by weight or more, and particularly preferably 20 parts by weight or more with respect to 100 parts by weight of the fiber material substrate. The amount is preferably 150 parts by weight or less, more preferably 100 parts by weight or less, and particularly preferably 50 parts by weight or less.

The leather-like sheet of the present invention is obtained by subjecting the leather-like sheet material obtained as described above to further post-processing treatment such as dyeing, washing, grinding and / or drying.
Dyeing can be performed by a known dyeing method such as using a circular dyeing machine. Although it does not specifically limit as dye used for dyeing | staining, Dyes mainly having a disperse dye, a metal complex dye, an acidic dye, etc. are mentioned.
Washing is performed to remove unreacted dyes, activators, inorganic salts, and the like. The washing method is not particularly limited, and examples include washing with a circular dyeing machine using warm water or cold water, impregnating in a water bath and squeezing with a mangle or the like.
Grinding is performed to raise the artificial leather surface. Although it does not specifically limit as a grinding method, The method using an emery puff machine etc. is mentioned.
Drying is performed to remove moisture after impregnation or to improve the strength of the resin. The drying method is not particularly limited, and examples thereof include hot air drying using a pin tenter or the like, infrared heating, and microwave heating.

The leather-like sheet of the present invention is extremely useful because it has moderate leather strength and improved abrasion resistance, and has a good texture similar to that of natural leather. Further, the leather-like sheet of the present invention can be suitably used for various applications, for example, mattresses, lining materials, clothing, shoe core materials, cushion fabrics, automobile interior materials, wall materials, and the like.

[Example]
EXAMPLES Hereinafter, although an Example demonstrates this invention further, this invention is not limited to these. In the following, “part” means part by weight.

Moreover, Mn described in the production examples was determined from the hydroxyl value measured by the method defined in JIS-K0070-1992 (potentiometric titration method).

<Production of polyurethane resin (a) emulsion>
Production Example 1
In a closed reaction vessel equipped with a thermometer and a stirrer, 330 parts of polyhexamethylene carbonate diol having a Mn of 2,000, 6.5 parts of 2,2-dimethylolpropionic acid (DMPA), 98 parts of 4,4′-dicyclohexylmethane diisocyanate 235 parts of acetone and acetone were charged, and the reaction system was replaced with nitrogen gas, followed by reaction at 90 ° C. for 10 hours with stirring to obtain an acetone solution of a terminal NCO-based urethane prepolymer. The obtained acetone solution was cooled to 40 ° C., and 5.0 parts of triethylamine was added. Next, (c) “Narrow Acty N-120” (manufactured by Sanyo Chemical Industries, Ltd., HLB 14.2; cloud point 77 ° C.) 21.7 parts dissolved in 412 parts water was added to the acetone solution. In addition, after stirring for 1 minute with a homomixer and emulsifying, a solution obtained by dissolving 1.0 part of ethylenediamine in 230 parts of water was added to cause a chain extension reaction, and then acetone was distilled off under reduced pressure. By adjusting, a polyurethane resin emulsion-1 having a non-volatile residue of 40% and an average dispersed particle size of 0.5 μm was obtained.
The content rate of the carboxylate group based on the weight of (a) in the obtained polyurethane resin emulsion-1 was 0.51%.

Production Example 2
Copolymer polycarbonate diol of 3-methyl-1,5-pentanediol / 1,6-hexanediol of Mn 2,000 instead of polyhexamethylene carbonate diol of Mn 2,000, “Emalmine NL-70” as (c) A polyurethane resin emulsion-2 was obtained in the same manner as in Production Example 1, except that [manufactured by Sanyo Chemical Industries, Ltd., HLB 12.4, cloud point 44 ° C.] was used.
The content rate of the carboxylate group based on the weight of (a) in the obtained polyurethane resin emulsion-2 was 0.50%.

Production Example 3
Other than using "Nonipol 500" [nonylphenol EO adduct, manufactured by Sanyo Chemical Industries, HLB 18.2, cloud point 100 ° C or higher] instead of "Narrow Acty N-120" in (c). Produced polyurethane resin emulsion-3 in the same manner as in Production Example 1.
The content rate of the carboxylate group based on the weight of (a) in the obtained polyurethane resin emulsion-3 was 0.48%.

<Manufacture of non-woven fabric>
Production Example 4
A laminated sheet is made from polyethylene terephthalate short fibers, and this sheet is needle punched so that the number of shots is 280 pieces / cm 2, then dried, and a nonwoven fabric A having a weight of 380 g / m 2 and an apparent density of 0.18 g / cm 2 is obtained. Obtained.

Comparative production example 1
Nonwoven fabric A is impregnated with emulsion type silicone “SM8706” (manufactured by Toray Dow Corning Co., Ltd.) diluted to a pure content of 5% and dried at 120 ° C. for 20 minutes, and the adhesion rate of silicone to the nonwoven fabric is 2%. Nonwoven fabric B was obtained.

Example 1
For 100 parts of polyurethane resin emulsion-1, 3 parts of emulsion type silicone “SM8706” [manufactured by Toray Dow Corning Co., Ltd.] is added as (b), and 8 parts of 10% aqueous solution of calcium chloride is added as (d). Water was added to adjust the non-volatile residue to 20% to obtain a heat-sensitive coagulable emulsion according to the present invention. The emulsion is impregnated with non-woven fabric A, squeezed with mangle so that the adhesion rate of the resin is about 30% with respect to the weight of the non-woven fabric, heated in saturated steam at 100 ° C. for 2 minutes, and further dried with hot air at 120 ° C. After drying with a machine for 20 minutes, it was washed with water and again dried with a hot air dryer at 120 ° C. for 20 minutes to obtain a leather-like sheet material.

Example 2
A leather-like sheet material was obtained in the same manner as in Example 1 except that 6 parts of emulsion type silicone “KM797” [manufactured by Shin-Etsu Chemical Co., Ltd.] was used as (b).

Example 3
A leather-like sheet material was obtained in the same manner as in Example 1 except that 6 parts of emulsion type fluorine-based compound “Dickguard F-90N” [Dainippon Ink Chemical Co., Ltd.] was used as (b). .

Example 4
A leather-like sheet material was obtained in the same manner as in Example 1 except that the polyurethane resin emulsion-2 was used instead of the polyurethane resin emulsion-1.

Comparative Example 1
A leather-like sheet material was obtained in the same manner as in Example 1 except that polyurethane resin emulsion-3 was used instead of polyurethane resin emulsion-1.

Comparative Example 2
A leather-like sheet material was obtained in the same manner as in Example 1 except that (d) was not added.

Comparative Example 3
A leather-like sheet material was obtained in the same manner as in Example 1 except that (b) was not added.

Comparative Example 4
A leather-like sheet material was obtained in the same manner as in Example 4 except that (b) was not added.

Comparative Example 5
A leather-like sheet material was obtained in the same manner as in Comparative Example 3 except that the nonwoven fabric B was used instead of the nonwoven fabric A.

Tables 1 and 2 show the components of the heat-sensitive coagulable emulsion and the heat-sensitive coagulation temperature used in Examples and Comparative Examples, and the types of nonwoven fabric used.
The thermal coagulation temperature was measured by reading the temperature at which the emulsion was heated and solidified and stopped flowing with a thermometer.

<Performance test>
The leather-like sheet materials produced in the examples and comparative examples were evaluated for resin adhesion rate (% by weight), abrasion resistance (average length of fluff) and texture by the following evaluation methods. The results are shown in Tables 1 and 2.
[Adhesion rate of resin (% by weight)]
It was calculated by the following formula.
100 × [(weight of leather-like sheet material) − (weight of fiber material substrate)] / (weight of fiber material substrate)
[Abrasion resistance]
When the surface of the leather-like sheet material was tested 500 times with a wear wheel H-18 at a load of 1 kg using a Taber type abrasion tester, the ground surface of the sheet was observed with a scanning electron microscope, and the average length of fluff Evaluation was made by thickness (μm), and it was determined that a long fluff was good without being cut by a wear test.
[Texture]
If the leather-like sheet material has a natural leather-like texture, it will be judged as “○”, and if it is slightly inferior in comparison with natural leather, “△”. The case where no texture was exhibited was determined as “x”. Judgment was made by a sensory test based on the hand touch.

The method for producing a leather-like sheet material of the present invention does not require an additional step of applying a soft water repellent, is excellent in productivity, and the obtained leather-like sheet material is excellent in texture and abrasion resistance. The leather-like sheet material and leather-like sheet obtained by the production method of the present invention are useful for mattresses, lining materials, clothing, shoe core materials, cushioning fabrics, automobile interior materials, wall materials, and the like.

Claims (6)

A method for producing a leather-like sheet material by applying a heat-sensitive coagulation emulsion (A) to a fiber material substrate that has not been subjected to a flexible water-repellent treatment, and then heat-coagulating the material. , Polyurethane resin (a), flexible water repellent (b), nonionic surfactant (c) having a cloud point of 40 to 98 ° C. and inorganic salt (d) as essential components, and weight ratio (b) / ( A method for producing a leather-like sheet material, wherein a) is an emulsion of 0.005 to 0.2. The method for producing a leather-like sheet material according to claim 1, wherein (a) is a polyurethane resin containing 0.01 to 1.5% by weight of a carboxylate group and / or a sulfonate group based on the weight of (a). The method for producing a leather-like sheet material according to claim 1 or 2, wherein (b) is a silicone compound and / or a fluorine compound. The method for producing a leather-like sheet material according to any one of claims 1 to 3, wherein the heat-sensitive coagulation is performed at an atmospheric temperature of 40 to 180 ° C. The leather-like sheet material obtained with the manufacturing method in any one of Claims 1-4. A leather-like sheet obtained by further post-processing the leather-like sheet material according to claim 5.